Hibbert dislocated his knee against Stockport on Tuesday and Johnson now wants to recruit a new forward, but with Craig Mackail-Smith and Aaron Mclean scoring 22 goals between them already, is finding it hard to persuade players to come to London Road.
He said: "Forwards might look at the fact that we have the two top scorers in the division and think why should they bother coming to us, but we have discussed a few names and we will make some recommendations to the chairman.
"We know Lee Tomlin can play up top so we do have an option, but Dave Hibbert has been incredibly unlucky since he arrived at the club.
"He has had limited opportunities, but he's been a superb professional and we all feel for him now.
"We will have to wait until the swelling on his knee goes down before he can have a scan. We will then be able to assess the recovery period properly, but he will be out for months."
Source: PA
Source: PA